Usain Bolt failed to break the ten-second barrier in his first 100-metre race of 2012 at a meeting in Ostrava.

Bolt, getting ready for a season that many expect to end in Olympic gold at London 2012, has regularly expressed his hope that he can run the 100m in 9.4 seconds - but on Friday he could only stop the clock in 10.04 seconds, although he nevertheless won the race.

Kim Collins finished second in 10.19sec, with American Darivs Patton third in 10.22sec and Britain's Dwain Chambers adrift of the three at 10.28s - outside the Olympic qualifying standard.

With a noticeable headwind also affecting the field, the Jamaican nevertheless admitted he was bemused by his performance - blaming a poor start and inability to propel himself through the 'drive' phase of the race.

"I don't really know what went on," Bolt said. "At the start, I didn't feel as explosive as I normally feel. If you don't get that first start, well, that's where my power comes from for the transition and everything comes together.

"That's reality, a very bad day at the starting blocks. I don't know exactly where it went wrong. I was looking forward to coming here and doing a good time. I guess it's just one of those days."

He added: "When I was warming up, I did some starts and I was flying. I ran out and didn't get going, couldn't generate speed up in middle of race so I had to work hard to get some speed up.

"I'll go back, look at the replay, talk to my coach and he can explain what I need to do and then I can go to Rome and improve on my time."

Elsewhere, there was a mixed bag of performances for British athletes. Christine Ohuruogu was second behind arch-rival Sanya Richards-Ross in the women's 400m, while Tiffany Porter underlined her Olympic medal credentials with an impressive win in the 100m hurdles - equalling the meeting record of 12.56s.

It was a different story in the men's hurdles, as world bronze medallist Andy Turner found himself down in sixth as Britain's three competitors (also including Andy Pozzi and Lawrence Clarke) all finished behind their American rivals.

Andre Osagie continued his encouraging form by taking a narrow second in the 800m behind European indoor champion Adam Kszczot, although Joe Thomas unfortunately finished last.
Kenyan prodigy Isiah Koech was the big winner in the 3000m with Andy Baddeley a distant third, although he nevertheless recorded a new personal best of 7min 37.14s.

Finally, Perri Shakes-Drayton finished third in the women's 400m hurdles.

After enduring a tricky start to his Manchester United career, perhaps it is fair that Marcos Rojo celebrated so boisterously as he watched his first professional club Estudiantes beat fierce rivals Gimnasia